Flight Model Behavior

[EGT]

Hi,

I have the latest version of the TBM900 (fantastic aircraft) but I'm having a few "minor" issues with it...

1) Setting the correct rudder for takeoff (blue index) results in incorrect takeoff behavior

2) Yaw due to thrust (P-Factor) appears to be backwards (pulls right instead of left)

3) The aircraft initially rotates correctly, but as it gains speed through 100-120 kts there is a sharp pitch-up tendency requiring a lot of down elevator to counter after lift-off which is unnatural

4) The aircraft has some torque induced roll, but this seems very...chaotic and requires a lot of correction which seems to just disappear

I'm running the latest version (1.1.12), and I'm *NOT* using the experimental flight model.

Anyone any suggestions?

EDIT: Seems I posted in the wrong forum. Can this be moved to support, please?

Edited July 1, 2020 by EGT

[Goran_M]

We can leave it here.  

Are you using FSEconomy?  FSEconomy has a tendency to mess with the CG due to the config file being for an 850.

[EGT]

Hi,

No. Just the TBM, JR SF260, and DF B407. Everything else is stock.

The aileron roll issue was a consequence of setting rudder trim for takeoff. I have since read that you removed p-factor, and consequently setting rudder trim just meant I was slipping the aircraft during takeoff, hence the weird behavior.

The pitch issue still persists however. It seems related to ground effect. Once out of ground effect and climbing away, elevator pressure required is forward, but constant until trimmed.

The pitch trim is extremely sensitive, too.

I am flying a light aircraft - 100 gal. fuel, one pilot, minimal baggage (30 lbs) in the aft hold. CoG is displaying as dead-center to the allowable range.

Edited July 2, 2020 by EGT

[Goran_M]

In all the cases I've seen, this is down to something on the individuals computer.  Can you join the discord and ask "totoritko" (Saso) about this.  He's the one that made the flight model, and is more suited to help you out.

https://discord.gg/T2J3p9

[EGT]

2 hours ago, Goran_M said:

In all the cases I've seen, this is down to something on the individuals computer.  Can you join the discord and ask "totoritko" (Saso) about this.  He's the one that made the flight model, and is more suited to help you out.

https://discord.gg/T2J3p9

Hmm. Sure! Joined.

[fchiari]

I am seeing exactly the same problems as @EGT (wonderful description btw). It seems to have improved by setting the experimental flight mode to ON, however on short final with Landign Flaps the acf becomes very instable. (Also no FSEconomy or any of that kind installed. Fresh XP 11.50 B13 with the latest TBM version...

[EGT]

On 7/8/2020 at 8:08 PM, fchiari said:

I am seeing exactly the same problems as @EGT (wonderful description btw). It seems to have improved by setting the experimental flight mode to ON, however on short final with Landign Flaps the acf becomes very instable. (Also no FSEconomy or any of that kind installed. Fresh XP 11.50 B13 with the latest TBM version...

Thank you.

What approach speed are you using? I approach at 90 kts.

The trim is still sensitive, though improved with the experimental flight model. Decelerating particularly through around 120 kts and config changes does require some careful trimming.

[youretootall]

I would like to follow this discussion. @Goran_M, could I have Discord invite please?

I agree closely with EGT's comments.  I last flew the TBM in earnest more than a year ago, and I remembered it needed bootful of right rudder on takeoff, which seemed realistic (real pilot here, have flown a single engine turboprop, just not a TBM).  There is significant instability using the standard flight model, experimental FM + some aggressive joystick curves improves this situation.  However, the left-turning tendencies are now subdued to the point of being regressive, as I end up using some left pedal on every takeoff.

[Goran_M]

1 hour ago, youretootall said:

I would like to follow this discussion. @Goran_M, could I have Discord invite please?

I agree closely with EGT's comments.  I last flew the TBM in earnest more than a year ago, and I remembered it needed bootful of right rudder on takeoff, which seemed realistic (real pilot here, have flown a single engine turboprop, just not a TBM).  There is significant instability using the standard flight model, experimental FM + some aggressive joystick curves improves this situation.  However, the left-turning tendencies are now subdued to the point of being regressive, as I end up using some left pedal on every takeoff.

https://discord.gg/WUe5qT